The parents of Tiana Parker, 7, had already informed officials at Deborah Brown Community School they would not shear off her dreadlocks to comply with a policy they thought only applied to boys, the Tulsa World reported Monday.
The charter school's categorization of dreadlocks and other "natural" hairstyles for African-American students as forbidden "faddish styles" has sparked public outrage, the newspaper said.
Tiana's story has been reported on internationally, and an online petition, calling for the revocation of the school's charter if it does not publicly apologize to the girl and her family, has garnered 17,000 signatures, the website Credomobilize.com said.
A public relations firm representing Langston University, sponsor of the charter school, said a policy change "to respect the individuality of students" was in preparation.
Tiana's father, Terrance, noted nothing was said in school when the girl's hair was braided into dreadlocks in March, but it became a problem two weeks into the new school year.
"Your hair should not be what you're judged by. I felt like she was unwanted," he said.
Tiana's parents said they would welcome an apology from the school but have no interest in returning her there.
"She is very happy at Anderson," an elementary school in the Tulsa public schools system where Tiana transferred, her mother Miranda said. "They welcomed her, and said they loved her hair."